This paper describes the new and large hot-cathode mercury-vapor rectifier tube that is used in the plate power rectifier of the Crosley (WLW) 500-kilowatt broadcast transmitter. Design features resulting in improved operation of mercury-vapor tubes are discussed together with the operating characteristics. An analysis of the advantages of the unit half-wave type of rectifier tube is made. View full abstract»

The work described in a previous paper1 is extended and revised. An alternative method of solving the fundamental equation is presented. Application to the positive grid oscillator is treated and oscillation criteria in general are discussed. View full abstract»

This method is essentially a means for continuously measuring the percentage of elapsed time during which the noise level exceeds a certain predetermined voltage level. The predetermined voltage level may be made any level at which data are desired. The device consists of a biased tube circuit such that when input signal exceeds a certain level, the output tube passes a normal value of plate current through a ballistic meter of slow period. If the input continuously exceeds the threshold level, the ballistic meter reads “100 per cent.” The data obtained are particularly useful in connection with the engineering of short-wave radiotelegraph circuits, since these are usually operated through vacuum tube relay devices at the receiving end, set to register normal output whenever1 the signal “marks” at any level above a controllable threshold value. View full abstract»

It is shown that a meteor of average velocity has enough energy to cause ionization of atmospheric gases by impact. Recent experimental work by Frische and others on collisions of ions is interpreted as supporting the hypothesis that meteoric collisions do result in ionization. The afterglow of nitrogen is considered as a possible example of the process by which a meteor train remains glowing for a period of minutes and the coincidence of the region in which such trains are generally observed and of the E region of the upper atmosphere is pointed out. The spectra of bright meteors, while not showing atmospheric lines, are shown not to be inconsistent with the above hypothesis. The behavior of the transatlantic short-wave radio telephone circuits of the American Telephone and Telegraph Company, during 1930, 1931, and 1932, is examined for possible meteoric effects. It is concluded that, in general, a rather large shower is necessary to affect them appreciably. This was to be expected since these circuits are normally under a continuous bombardment by random meteors. It seems possible that a certain degree of the variability (rapid fading, etc.) of received signals over such paths is due to this bombardment. Results of radio pulse studies of the upper atmosphere, particularly by Schafer and Goodall, which are strongly suggestive of meteoric ionization, especially at times of special meteoric activity, are (1) sudden increases in ionizaton in the E region lasting for a period of minutes or less, and (2) increases of longer duration with maxima coincident in time with those of observed meteoric activity. Such tests made during the Leonid shower of November, 1932, were successful in correlating sudden increases in ionization in the E region with the visual observations of a number of bright meteors passing overhead. For the brightest meteor observed, the ionization increased to a value in excess of summer noon conditions. It is pointed out that meteoric showers might ta- e place in the F region which would be unobservable by ordinary visual means. Taking into account the energy spent by the meteor in ionization, a mass for the brightest meteor, for which correlative data was obtained is roughly calculated to be 0.3 gram. Its estimated brightness was −1 magnitude. The recombination coefficient at the height of the E region is calculated from the rate of decrease of ionization after the passage of a meteor, to be less than 0.2 × 10−8 cubic centimeters per second. View full abstract»

The complex impedance of a vertical half-wave antenna located any distance above an earth of given conductivity and dielectric constant is calculated by the “induced electromotive force” method. Based on the assumption k0≪ |k| (where k0 and k are the wave numbers for the atmosphere and earthy respectively), the results are applicable down to about 10 meters for any earth except a very dry soil. The calculation is based on the Sommerfeld-von Hoerschlemann expression for the field of a dipole above a half space of arbitrary electrical character. After splitting the total impedance into three parts, Z = Z1 + Z2 + Z3, the component Z1 is shown to be the self-impedance of the antenna, Z2 the mutual impedance between the antenna and its perfect image, and Z3 an impedance component due to the finite conductivity of the earth. Z3 is found to be proportional to two factors, one of which depends on the conductivity and dielectric coefficient of the earth and the wavelength and the other of which depends only on the ratio h/λ, where h = antenna height and λ = wavelength. Z3 is put in a form suitable for the computation of any given case and curves are shown for four typical examples. For λ > 10 meters and all except very dry soil, the effect of the finite conductivity is quite small and the assumption, often made, of a perfectly reflecting earth thus is justified for a large number of cases. The impedance is, except for very short waves or exceedingly dry soil, substantially that obtained for a perfectly conducting earth. A principle of similitude is stated, in which two antennas over the same kind of earth and having equal values of h/λ have identical impedances. View full abstract»

This paper deals with various electrical magnitudes involved in the process of radiation from an ordinary antenna. The calculations presented are based on the simplified assumptions of a highly conducting earth and a sinusoidal distribution of antenna current. Also, they neglect any components of the near-by field that may be associated with the flat top. The paper is divided into four main parts and an appendix. In the first party the relative magnitudes and phases of earth currents associated with radiation from antennas of four representative proportions are calculated. The results are shown in Figs. 3 and 4. In the second party both the displacement current density and the electric intensity are studied quantitatively. The results are shown in Fig. 5. The third part consists of an experimental verification of the calculated magnetic flux near an antenna. The agreement is evident from Fig. 6. In the last section, the theory is applied to a simple half-wave antenna with a view to localizing the earth losses. These are found to be greatest at a distance from the base of the antenna of 0.35λ. This is indicated by Fig. 7. An appendix points out the magnitude of error in neglecting components of the near-by field associated with the fiat top. View full abstract»